This invention relates to chromium-cobalt fine alloy powder and to the process for producing the powder by a two step reduction of a mixture of the chlorides of chromium and cobalt.
Fine powders of the more easily reduced metals such as iron, cobalt, nickel, and copper are typically prepared via the temperature controlled hydrogen reduction of the corresponding metal oxides. This method of preparation allows for precise control over such properties as particle size, surface area, and porosity of the metal powder. Alloy fine powders can similarly be prepared by reduction of mixed metal oxides. However, the hydrogen reduction of oxophilic metals such as chromium does not proceed significantly at temperatures below 1000.degree. C. if the metal oxide is used as the starting material. Therefore, reduction of mixtures of oxides containing, for example, chromic oxide do not proceed to completion.
Chromium-cobalt metal alloys, in particular fine alloy powders are useful in cemented carbides. Therefore, a process to produce such alloys from chromium sources other than oxides and therefore at temperatures lower than 1000.degree. C. would be desirable.